Purposefully designing novel hydroxylated and carbonylated melamine towards the synthesis of targeted porous oxygen-doped g-C3N4 nanosheets for highly enhanced photocatalytic hydrogen production

Abstract

Graphitic carbon nitride (g-C₃N₄) has been considered as a promising metal-free photocatalyst, but the bulk still suffers from a low specific surface area and poor quantum efficiency. Exfoliation of the bulk into porous heteroatom-doped nanosheets has been confirmed to be an effective strategy for improving the photocatalytic activity. However, purposefully designing targeted precursors towards the synthesis of porous heteroatom-doped g-C₃N₄ nanostructures for enhanced photocatalytic activity is still a challenge. Here, we intentionally design and construct a new hydroxylated and carbonylated melamine precursor for preparing targeted porous O-doped g-C₃N₄ nanosheets based on the thermal polymerization reaction pathway. The as-prepared porous O-doped g-C₃N₄ nanosheets possess a high specific surface area which provides more active sites, and exhibit enhanced transfer and separation of charge carriers, thus displaying an about 18-fold higher hydrogen production activity than the bulk counterpart. This work would stimulate widespread investigations into the development of a designated precursor-reforming strategy for synthesizing highly-active g-C₃N₄ photocatalysts.